编程题要有题目，而且要有答案，越多越好，谢谢！
一、8253
.MODEL TINY
PCIBAR3 EQU 1CH ;8位I/O空间基地址(它就是实验仪的基地址,也为DMA & 32 BIT RAM板卡上的8237提供基地址)
Vendor_ID EQU 10EBH ;厂商ID号
Device_ID EQU 8376 ;设备ID号
.STACK 100
.DATA
COM_ADDR DW 00B3H
T0_ADDR DW 00B0H
T1_ADDR DW 00B1H
IO_Bit8_BaseAddress DW
msg0 DB 'BIOS不支持访问PCI
msg1 DB '找不到Star PCI9052板卡
msg2 DB '读8位I/O空间基地址时出错
.CODE
START: MOV AX,@DATA
MOV DS,AX
NOP
CALL InitPCI
CALL ModifyAddress ;根据PCI提供的基地址,将偏移地址转化为实地址
mov dx,COM_ADD
mov al,35h;?
out dx,al ;计数器T0设置在模式2状态,BCD码计数
mov dx,T0_ADDR
mov al,00h
out dx,al
mov al,10h
out dx,al ;CLK0/1000
mov dx,COM_ADDR
mov al,77h
out dx,al ;计数器T1为模式3状态，输出方波,BCD码计数
mov dx,T1_ADDR
mov al,00h
out dx,al
mov al,10h
out dx,al ;CLK1/1000
START1: CALL IfExit ;OUT1输出频率为1S的方波
JZ START1
JMP Exit
IfExit PROC NEAR
PUSH AX
PUSH DX
MOV AH,06H
MOV DL,0FFH
INT 21H
POP DX
POP AX
RET
IfExit ENDP
InitPCI PROC NEAR
MOV AH,00H
MOV AL,03H
INT 10H ;清屏
MOV AH,0B1H
MOV AL,01H
INT 1AH
CMP AH,0
JZ InitPCI2
LEA DX,msg0
InitPCI1: MOV AH,09H
INT 21H
JMP Exit
InitPCI2: MOV AH,0B1H
MOV AL,02H
MOV CX,Device_ID
MOV DX,Vendor_ID
MOV SI,0
INT 1AH
JNC InitPCI3 ;是否存在Star PCI9052板卡
LEA DX,msg1
JMP InitPCI1
InitPCI3: MOV DI,PCIBAR3
MOV AH,0B1H
MOV AL,09H
INT 1AH ;读取该卡PCI9052基地址
JNC InitPCI4
LEA DX,msg2
JMP InitPCI1
InitPCI4: AND CX,0FFFCH
MOV IO_Bit8_BaseAddress,CX
RET
InitPCI ENDP
ModifyAddress PROC NEAR
ADD COM_ADDR,CX
ADD T0_ADDR,CX
ADD T1_ADDR,CX
RET
ModifyAddress ENDP
Exit: MOV AH,4CH
INT 21H
END START
二、8259
.MODEL TINY
PCIBAR1 EQU 14H ;PCI9052 I/O基地址（用于访问局部配置寄存器）
PCIBAR3 EQU 1CH ;8位I/O空间基地址(它就是实验仪的基地址,也为DMA & 32 BIT RAM板卡上的8237提供基地址)
PCIIPR EQU 3CH ;IRQ号
INTCSR EQU 4CH ;PCI9052 INTCSR地址
mask_int_9052 EQU 24H
Vendor_ID EQU 10EBH ;厂商ID号
Device_ID EQU 8376 ;设备ID号
.STACK 100
.DATA
IO8259_0 DW 00F0H
IO8259_1 DW 00F1H
RD_IO8259 DW 0000H
IO_Bit8_BaseAddress DW ?
PCI_IO_BaseAddress0 DW ?
PCI_IRQ_NUMBER DB ?
INT_MASK DB ?
INT_Vector DB ?
INT_CS DW ? ;保护原中断入口地址
INT_IP DW ?
msg0 DB 'BIOS不支持访问PCI
msg1 DB '找不到Star PCI9052板卡
msg2 DB '读PCI9052 I/O基地址时出错$'
msg3 DB '读8位I/O空间基地址时出错$'
msg4 DB '读IRQ号出错$'
msg5 DB '8259中断 00H 次$'
BUFFER DB
Counter DB ?
ReDisplayFlag DB 0
.CODE
START: MOV AX,@DATA
MOV DS,AX
MOV ES,AX
NOP
CALL InitPCI
CALL ModifyAddress ;根据PCI提供的基地址,将偏移地址转化为实地址
CALL ModifyVector ;修改中断向量、允许中断
MOV AH,00H
MOV AL,03H
INT 10H ;清屏
MOV AH,09H
LEA DX,msg5
INT 21H
CALL Init8259
MOV Counter,0 ;中断次数
MOV ReDisplayFlag,1 ;需要显示
STI ;开中断
START1: CALL IfExit
CMP ReDisplayFlag,0
JZ START1
CALL LedDisplay
MOV ReDisplayFlag,0
JMP START1
Init8259 PROC NEAR
MOV DX,IO8259_0
mov al,13H
out dx,al
MOV DX,IO8259_1
mov al,08H
out dx,al
MOV AL,09H
OUT DX,AL
mov al,0feH ;屏蔽寄存器
OUT DX,AL
RET
Init8259 ENDP
ToChar PROC NEAR ;转化为可显示的16进制数
ADD AL,'0'
CMP AL,'9'
JBE ToChar1
ADD AL,07H
ToChar1: RET
ToChar ENDP
LedDisplay PROC NEAR
MOV AL,Counter
MOV AH,AL
AND AL,0FH
CALL ToChar
MOV Buffer + 1,AL
AND AH,0F0H
ROR AH,4
MOV AL,AH
CALL ToChar
MOV Buffer,AL
MOV AH,02H
MOV DL,10
MOV DH,0
INT 10H ;定位光标
MOV AH,09H
LEA DX,Buffer
INT 21H
RET
LedDisplay ENDP
INT_0: PUSH DX
PUSH AX
CALL ClearInt
JC INT_0_0
MOV DX,RD_IO8259
IN AL,DX
IN AL,DX ;判断由哪个中断源引起的中断
MOV AL,Counter
ADD AL,1
DAA
MOV Counter,AL
MOV ReDisplayFlag,1
INT_0_0: MOV DX,IO8259_0
MOV AL,20H
OUT DX,AL
POP AX
POP DX
IRET
IfExit PROC NEAR
PUSH AX
PUSH DX
MOV AH,06H
MOV DL,0FFH
INT 21H
POP DX
POP AX
JZ IfExit1
JMP Exit
IfExit1: RET
IfExit ENDP
InitPCI PROC NEAR
MOV AH,00H
MOV AL,03H
INT 10H ;清屏
MOV AH,0B1H
MOV AL,01H
INT 1AH
CMP AH,0
JZ InitPCI2
LEA DX,msg0
InitPCI1: MOV AH,09H
INT 21H
JMP Exit
InitPCI2: MOV AH,0B1H
MOV AL,02H
MOV CX,Device_ID
MOV DX,Vendor_ID
MOV SI,0
INT 1AH
JNC InitPCI3 ;是否存在Star PCI9052板卡
LEA DX,msg1
JMP InitPCI1
InitPCI3: MOV DI,PCIBAR1
MOV AH,0B1H
MOV AL,09H
INT 1AH ;读取该卡PCI9052基地址
JNC InitPCI4
LEA DX,msg2
JMP InitPCI1
InitPCI4: AND CX,0FFFCH
MOV PCI_IO_BaseAddress0,CX
MOV DI,PCIBAR3
MOV AH,0B1H
MOV AL,09H
INT 1AH ;读取该卡扩展的8位IO基地址
JNC InitPCI5
LEA DX,msg3
JMP InitPCI1
InitPCI5: AND CX,0FFFCH
MOV IO_Bit8_BaseAddress,CX
MOV DI,PCIIPR
MOV AH,0B1H
MOV AL,09H
INT 1AH ;读取IRQ号
JNC InitPCI6
LEA DX,msg4
JMP InitPCI1
InitPCI6: MOV PCI_IRQ_NUMBER,CL
RET
InitPCI ENDP
ModifyAddress PROC NEAR
MOV AX,IO_Bit8_BaseAddress
ADD IO8259_0,AX
ADD IO8259_1,AX
ADD RD_IO8259,AX
RET
ModifyAddress ENDP
ModifyVector PROC NEAR
PUSH ES
MOV AL,PCI_IRQ_NUMBER
CMP AL,08H
JAE ModifyVector1
ADD AL,08H ;IRQ0..7 -> 中断向量8..F
JMP ModifyVector2
ModifyVector1: ADD AL,70H-08H ;IRQ8..F -> 中断向量70H..77H
ModifyVector2: MOV INT_Vector,AL
MOV AH,35H
INT 21H
MOV INT_IP,BX ;保护原中断处理例程地址
MOV AX,ES
MOV INT_CS,AX
MOV AL,INT_Vector
LEA DX,INT_0
PUSH DS
PUSH CS
POP DS
MOV AH,25H
INT 21H ;设置新中断向量
POP DS
MOV BL,PCI_IRQ_NUMBER
MOV DX,21H
CMP AL,08H
JB ModifyVector3
MOV DX,0A1H
ModifyVector3: IN AL,DX
MOV INT_MASK,AL
AND BL,07H
MOV CL,BL
MOV BL,1
SHL BL,CL
NOT BL
AND AL,BL
OUT DX,AL ;允许中断
POP ES
STI
RET
ModifyVector ENDP
ClearInt PROC NEAR ;清楚PCI9052、系统中断控制器的中断标志
MOV DX,PCI_IO_BaseAddress0
ADD DX,INTCSR
; IN AL,DX
; AND AL,mask_int_9052
; JZ ClearInt3 ;不是8259引取的中断
INC DX
IN AL,DX
OR AL,0CH
OUT DX,AL ;清除PCI9052的中断标志位
MOV AL,PCI_IRQ_NUMBER
CMP AL,08H
JAE ClearInt1
AND AL,7
OR AL,60H
MOV DX,20H
OUT DX,AL
JMP ClearInt2
ClearInt1: AND AL,7
OR AL,60H
MOV DX,0A0H
OUT DX,AL
MOV DX,20H
MOV AL,62H
OUT DX,AL
ClearInt2: CLC
RET
;ClearInt3: STC
; RET
ClearInt ENDP
Exit: CLI
MOV BL,PCI_IRQ_NUMBER
MOV DX,21H
CMP AL,08H
JB Exit1
MOV DX,0A1H
Exit1: MOV AL,INT_MASK
OUT DX,AL ;屏蔽中断
PUSH DS
MOV AL,INT_Vector
MOV DX,INT_IP ;保护原中断处理例程地址
MOV AX,INT_CS
MOV AH,25H
INT 21H ;设置新中断向量
POP DS
STI
MOV AH,4CH
INT 21H
END START
三、8251
.MODEL TINY
;使用8253的计数器0,外接2Mhz,经26分频后,送给8251,产生4800bps
PCIBAR3 EQU 1CH ;8位I/O空间基地址(它就是实验仪的基地址,也为DMA & 32 BIT RAM板卡上的8237提供基地址)
Vendor_ID EQU 10EBH ;厂商ID号
Device_ID EQU 8376 ;设备ID号
.STACK 100
.DATA
CTL_ADDR DW 00F1H ;控制字或状态字
DATA_ADDR DW 00F0H ;读写数据
W_8253_T0 DW 00B0H ;计数器0地址
W_8253_C DW 00B3H ;控制字
IO_Bit8_BaseAddress DW
msg0 DB 'BIOS不支持访问PCI
msg1 DB '找不到Star PCI9052板卡
msg2 DB '读8位I/O空间基地址时出错$'
Receive_Buffer DB 10 DUP(0) ;接受缓冲器
Send_Buffer EQU Receive_Buffer ;发送缓冲器
.CODE
START: MOV AX,@DATA
MOV DS,AX
MOV ES,AX
NOP
CALL InitPCI
CALL ModifyAddress ;根据PCI提供的基地址,将偏移地址转化为实地址
CALL INIT_8253
CALL INIT_8251
START1: MOV CX,10
CALL Receive_Group
MOV CX,10
CALL Send_Group
CALL IfExit ;OUT1输出频率为1S的方波
JZ START1
JMP Exit
; JMP START1
INIT_8253 PROC NEAR
MOV DX,W_8253_C
MOV AL,37H ;定时器0，方式3
OUT DX,AL
MOV DX,W_8253_T0
MOV AL,26H ;BCD码26(2000000/26)=16*4800
OUT DX,AL
MOV AL,0
OUT DX,AL
RET
INIT_8253 ENDP
INIT_8251 PROC NEAR
CALL RESET_8251
mov dx,CTL_ADDR
mov al,7eh ;波特率系数为16，8个数据位
out dxx,al ;一个停止位，偶校验
CALL DLTIME ;延时
mov al,15h ;允许接收和发送发送数据，清错误标志
out dx,al
CALL DLTIME
RET
INIT_8251 ENDP
Reset_8251 PROC NEAR
MOV DX,CTL_ADDR
MOV AL,0
OUT DX,AL ;向控制口写入"0"
CALL DLTIME ;延时，等待写操作完成
OUT DX,AL ;向控制口写入"0"
CALL DLTIME ;延时
OUT DX,AL ;向控制口写入"0"
CALL DLTIME ;延时
MOV AL,40H ;向控制口写入复位字40H
OUT DX,AL
CALL DLTIME
RET
Reset_8251 ENDP
;接受一组数据,CX--接受数目
Receive_Group PROC NEAR
LEA DI,Receive_Buffer
Receive_Group1: CALL Receive_Byte
STOSB
LOOP Receive_Group1
RET
Receive_Group ENDP
;接受一个字节
Receive_Byte PROC NEAR
MOV DX,CTL_ADDR
Receive_Byte1: in al,dx ;读入状态
test al,2
jz Receive_Byte1 ;
mov dx, DATA_ADDR ;有
in al,dx
RET
Receive_Byte ENDP
;发送一组数据,CX--发送数目
Send_Group PROC NEAR
LEA SI,Send_Buffer
Send_Group1: lodsb
call Sendbyte
loop Send_Group1
RET
Send_Group ENDP
;发送一个字节
Sendbyte PROC NEAR
PUSH AX
MOV DX,CTL_ADDR ;读入状态
Sendbyte1: in al,dx
test al,1
jz Sendbyte1 ;允许数据发送吗？
pop ax ;发送
mov dx,DATA_
MOV CX,Device_ID
MOV DX,Vendor_ID
MOV SI,0
INT 1AH
JNC InitPCI3 ;是否存在Star PCI9052板卡
LEA DX,msg1
JMP InitPCI1
InitPCI3: MOV DI,PCIBAR3
MOV AH,0B1H
MOV AL,09H
INT 1AH ;读取该卡PCI9052基地址
JNC InitPCI4
LEA DX,msg2
JMP InitPCI1
InitPCI4: AND CX,0FFFCH
MOV IO_Bit8_BaseAddress,CX
RET
InitPCI ENDP
ModifyAddress PROC NEAR
ADD COM_ADD,CX
ADD PA_ADD,CX
ADD PB_ADD,CX
ADD PC_ADD,CX
RET
ModifyAddress ENDP
Exit: MOV AH,4CH
INT 21H
END START
.MODEL TINY
PCIBAR3 EQU 1CH ;8位I/O空间基地址(它就是实验仪的基地址,也为DMA & 32 BIT RAM板卡上的8237提供基地址)
Vendor_ID EQU 10EBH ;厂商ID号
Device_ID EQU 8376 ;设备ID号
.STACK 100
.DATA
COM_ADDR DW 00B3H
T0_ADDR DW 00B0H
T1_ADDR DW 00B1H
IO_Bit8_BaseAddress DW
msg0 DB 'BIOS不支持访问PCI
msg1 DB '找不到Star PCI9052板卡
msg2 DB '读8位I/O空间基地址时出错
.CODE
START: MOV AX,@DATA
MOV DS,AX
NOP
CALL InitPCI
CALL ModifyAddress ;根据PCI提供的基地址,将偏移地址转化为实地址
mov dx,COM_ADD
mov al,35h;?
out dx,al ;计数器T0设置在模式2状态,BCD码计数
mov dx,T0_ADDR
mov al,00h
out dx,al
mov al,10h
out dx,al ;CLK0/1000
mov dx,COM_ADDR
mov al,77h
out dx,al ;计数器T1为模式3状态，输出方波,BCD码计数
mov dx,T1_ADDR
mov al,00h
out dx,al
mov al,10h
out dx,al ;CLK1/1000
START1: CALL IfExit ;OUT1输出频率为1S的方波
JZ START1
JMP Exit
IfExit PROC NEAR
PUSH AX
PUSH DX
MOV AH,06H
MOV DL,0FFH
INT 21H
POP DX
POP AX
RET
IfExit ENDP
InitPCI PROC NEAR
MOV AH,00H
MOV AL,03H
INT 10H ;清屏
MOV AH,0B1H
MOV AL,01H
INT 1AH
CMP AH,0
JZ InitPCI2
LEA DX,msg0
InitPCI1: MOV AH,09H
INT 21H
JMP Exit
InitPCI2: MOV AH,0B1H
MOV AL,02H
MOV CX,Device_ID
MOV DX,Vendor_ID
MOV SI,0
INT 1AH
JNC InitPCI3 ;是否存在Star PCI9052板卡
LEA DX,msg1
JMP InitPCI1
InitPCI3: MOV DI,PCIBAR3
MOV AH,0B1H
MOV AL,09H
INT 1AH ;读取该卡PCI9052基地址
JNC InitPCI4
LEA DX,msg2
JMP InitPCI1
InitPCI4: AND CX,0FFFCH
MOV IO_Bit8_BaseAddress,CX
RET
InitPCI ENDP
ModifyAddress PROC NEAR
ADD COM_ADDR,CX
ADD T0_ADDR,CX
ADD T1_ADDR,CX
RET
ModifyAddress ENDP
Exit: MOV AH,4CH
INT 21H
END START
二、8259
.MODEL TINY
PCIBAR1 EQU 14H ;PCI9052 I/O基地址（用于访问局部配置寄存器）
PCIBAR3 EQU 1CH ;8位I/O空间基地址(它就是实验仪的基地址,也为DMA & 32 BIT RAM板卡上的8237提供基地址)
PCIIPR EQU 3CH ;IRQ号
INTCSR EQU 4CH ;PCI9052 INTCSR地址
mask_int_9052 EQU 24H
Vendor_ID EQU 10EBH ;厂商ID号
Device_ID EQU 8376 ;设备ID号
.STACK 100
.DATA
IO8259_0 DW 00F0H
IO8259_1 DW 00F1H
RD_IO8259 DW 0000H
IO_Bit8_BaseAddress DW ?
PCI_IO_BaseAddress0 DW ?
PCI_IRQ_NUMBER DB ?
INT_MASK DB ?
INT_Vector DB ?
INT_CS DW ? ;保护原中断入口地址
INT_IP DW ?
msg0 DB 'BIOS不支持访问PCI
msg1 DB '找不到Star PCI9052板卡
msg2 DB '读PCI9052 I/O基地址时出错$'
msg3 DB '读8位I/O空间基地址时出错$'
msg4 DB '读IRQ号出错$'
msg5 DB '8259中断 00H 次$'
BUFFER DB
Counter DB ?
ReDisplayFlag DB 0
.CODE
START: MOV AX,@DATA
MOV DS,AX
MOV ES,AX
NOP
CALL InitPCI
CALL ModifyAddress ;根据PCI提供的基地址,将偏移地址转化为实地址
CALL ModifyVector ;修改中断向量、允许中断
MOV AH,00H
MOV AL,03H
INT 10H ;清屏
MOV AH,09H
LEA DX,msg5
INT 21H
CALL Init8259
MOV Counter,0 ;中断次数
MOV ReDisplayFlag,1 ;需要显示
STI ;开中断
START1: CALL IfExit
CMP ReDisplayFlag,0
JZ START1
CALL LedDisplay
MOV ReDisplayFlag,0
JMP START1
Init8259 PROC NEAR
MOV DX,IO8259_0
mov al,13H
out dx,al
MOV DX,IO8259_1
mov al,08H
out dx,al
MOV AL,09H
OUT DX,AL
mov al,0feH ;屏蔽寄存器
OUT DX,AL
RET
Init8259 ENDP
ToChar PROC NEAR ;转化为可显示的16进制数
ADD AL,'0'
CMP AL,'9'
JBE ToChar1
ADD AL,07H
ToChar1: RET
ToChar ENDP
LedDisplay PROC NEAR
MOV AL,Counter
MOV AH,AL
AND AL,0FH
CALL ToChar
MOV Buffer + 1,AL
AND AH,0F0H
ROR AH,4
MOV AL,AH
CALL ToChar
MOV Buffer,AL
MOV AH,02H
MOV DL,10
MOV DH,0
INT 10H ;定位光标
MOV AH,09H
LEA DX,Buffer
INT 21H
RET
LedDisplay ENDP
INT_0: PUSH DX
PUSH AX
CALL ClearInt
JC INT_0_0
MOV DX,RD_IO8259
IN AL,DX
IN AL,DX ;判断由哪个中断源引起的中断
MOV AL,Counter
ADD AL,1
DAA
MOV Counter,AL
MOV ReDisplayFlag,1
INT_0_0: MOV DX,IO8259_0
MOV AL,20H
OUT DX,AL
POP AX
POP DX
IRET
IfExit PROC NEAR
PUSH AX
PUSH DX
MOV AH,06H
MOV DL,0FFH
INT 21H
POP DX
POP AX
JZ IfExit1
JMP Exit
IfExit1: RET
IfExit ENDP
InitPCI PROC NEAR
MOV AH,00H
MOV AL,03H
INT 10H ;清屏
MOV AH,0B1H
MOV AL,01H
INT 1AH
CMP AH,0
JZ InitPCI2
LEA DX,msg0
InitPCI1: MOV AH,09H
INT 21H
JMP Exit
InitPCI2: MOV AH,0B1H
MOV AL,02H
MOV CX,Device_ID
MOV DX,Vendor_ID
MOV SI,0
INT 1AH
JNC InitPCI3 ;是否存在Star PCI9052板卡
LEA DX,msg1
JMP InitPCI1
InitPCI3: MOV DI,PCIBAR1
MOV AH,0B1H
MOV AL,09H
INT 1AH ;读取该卡PCI9052基地址
JNC InitPCI4
LEA DX,msg2
JMP InitPCI1
InitPCI4: AND CX,0FFFCH
MOV PCI_IO_BaseAddress0,CX
MOV DI,PCIBAR3
MOV AH,0B1H
MOV AL,09H
INT 1AH ;读取该卡扩展的8位IO基地址
JNC InitPCI5
LEA DX,msg3
JMP InitPCI1
InitPCI5: AND CX,0FFFCH
MOV IO_Bit8_BaseAddress,CX
MOV DI,PCIIPR
MOV AH,0B1H
MOV AL,09H
INT 1AH ;读取IRQ号
JNC InitPCI6
LEA DX,msg4
JMP InitPCI1
InitPCI6: MOV PCI_IRQ_NUMBER,CL
RET
InitPCI ENDP
ModifyAddress PROC NEAR
MOV AX,IO_Bit8_BaseAddress
ADD IO8259_0,AX
ADD IO8259_1,AX
ADD RD_IO8259,AX
RET
ModifyAddress ENDP
ModifyVector PROC NEAR
PUSH ES
MOV AL,PCI_IRQ_NUMBER
CMP AL,08H
JAE ModifyVector1
ADD AL,08H ;IRQ0..7 -> 中断向量8..F
JMP ModifyVector2
ModifyVector1: ADD AL,70H-08H ;IRQ8..F -> 中断向量70H..77H
ModifyVector2: MOV INT_Vector,AL
MOV AH,35H
INT 21H
MOV INT_IP,BX ;保护原中断处理例程地址
MOV AX,ES
MOV INT_CS,AX
MOV AL,INT_Vector
LEA DX,INT_0
PUSH DS
PUSH CS
POP DS
MOV AH,25H
INT 21H ;设置新中断向量
POP DS
MOV BL,PCI_IRQ_NUMBER
MOV DX,21H
CMP AL,08H
JB ModifyVector3
MOV DX,0A1H
ModifyVector3: IN AL,DX
MOV INT_MASK,AL
AND BL,07H
MOV CL,BL
MOV BL,1
SHL BL,CL
NOT BL
AND AL,BL
OUT DX,AL ;允许中断
POP ES
STI
RET
ModifyVector ENDP
ClearInt PROC NEAR ;清楚PCI9052、系统中断控制器的中断标志
MOV DX,PCI_IO_BaseAddress0
ADD DX,INTCSR
; IN AL,DX
; AND AL,mask_int_9052
; JZ ClearInt3 ;不是8259引取的中断
INC DX
IN AL,DX
OR AL,0CH
OUT DX,AL ;清除PCI9052的中断标志位
MOV AL,PCI_IRQ_NUMBER
CMP AL,08H
JAE ClearInt1
AND AL,7
OR AL,60H
MOV DX,20H
OUT DX,AL
JMP ClearInt2
ClearInt1: AND AL,7
OR AL,60H
MOV DX,0A0H
OUT DX,AL
MOV DX,20H
MOV AL,62H
OUT DX,AL
ClearInt2: CLC
RET
;ClearInt3: STC
; RET
ClearInt ENDP
Exit: CLI
MOV BL,PCI_IRQ_NUMBER
MOV DX,21H
CMP AL,08H
JB Exit1
MOV DX,0A1H
Exit1: MOV AL,INT_MASK
OUT DX,AL ;屏蔽中断
PUSH DS
MOV AL,INT_Vector
MOV DX,INT_IP ;保护原中断处理例程地址
MOV AX,INT_CS
MOV AH,25H
INT 21H ;设置新中断向量
POP DS
STI
MOV AH,4CH
INT 21H
END START
三、8251
.MODEL TINY
;使用8253的计数器0,外接2Mhz,经26分频后,送给8251,产生4800bps
PCIBAR3 EQU 1CH ;8位I/O空间基地址(它就是实验仪的基地址,也为DMA & 32 BIT RAM板卡上的8237提供基地址)
Vendor_ID EQU 10EBH ;厂商ID号
Device_ID EQU 8376 ;设备ID号
.STACK 100
.DATA
CTL_ADDR DW 00F1H ;控制字或状态字
DATA_ADDR DW 00F0H ;读写数据
W_8253_T0 DW 00B0H ;计数器0地址
W_8253_C DW 00B3H ;控制字
IO_Bit8_BaseAddress DW
msg0 DB 'BIOS不支持访问PCI
msg1 DB '找不到Star PCI9052板卡
msg2 DB '读8位I/O空间基地址时出错$'
Receive_Buffer DB 10 DUP(0) ;接受缓冲器
Send_Buffer EQU Receive_Buffer ;发送缓冲器
.CODE
START: MOV AX,@DATA
MOV DS,AX
MOV ES,AX
NOP
CALL InitPCI
CALL ModifyAddress ;根据PCI提供的基地址,将偏移地址转化为实地址
CALL INIT_8253
CALL INIT_8251
START1: MOV CX,10
CALL Receive_Group
MOV CX,10
CALL Send_Group
CALL IfExit ;OUT1输出频率为1S的方波
JZ START1
JMP Exit
; JMP START1
INIT_8253 PROC NEAR
MOV DX,W_8253_C
MOV AL,37H ;定时器0，方式3
OUT DX,AL
MOV DX,W_8253_T0
MOV AL,26H ;BCD码26(2000000/26)=16*4800
OUT DX,AL
MOV AL,0
OUT DX,AL
RET
INIT_8253 ENDP
INIT_8251 PROC NEAR
CALL RESET_8251
mov dx,CTL_ADDR
mov al,7eh ;波特率系数为16，8个数据位
out dxx,al ;一个停止位，偶校验
CALL DLTIME ;延时
mov al,15h ;允许接收和发送发送数据，清错误标志
out dx,al
CALL DLTIME
RET
INIT_8251 ENDP
Reset_8251 PROC NEAR
MOV DX,CTL_ADDR
MOV AL,0
OUT DX,AL ;向控制口写入"0"
CALL DLTIME ;延时，等待写操作完成
OUT DX,AL ;向控制口写入"0"
CALL DLTIME ;延时
OUT DX,AL ;向控制口写入"0"
CALL DLTIME ;延时
MOV AL,40H ;向控制口写入复位字40H
OUT DX,AL
CALL DLTIME
RET
Reset_8251 ENDP
;接受一组数据,CX--接受数目
Receive_Group PROC NEAR
LEA DI,Receive_Buffer
Receive_Group1: CALL Receive_Byte
STOSB
LOOP Receive_Group1
RET
Receive_Group ENDP
;接受一个字节
Receive_Byte PROC NEAR
MOV DX,CTL_ADDR
Receive_Byte1: in al,dx ;读入状态
test al,2
jz Receive_Byte1 ;
mov dx, DATA_ADDR ;有
in al,dx
RET
Receive_Byte ENDP
;发送一组数据,CX--发送数目
Send_Group PROC NEAR
LEA SI,Send_Buffer
Send_Group1: lodsb
call Sendbyte
loop Send_Group1
RET
Send_Group ENDP
;发送一个字节
Sendbyte PROC NEAR
PUSH AX
MOV DX,CTL_ADDR ;读入状态
Sendbyte1: in al,dx
test al,1
jz Sendbyte1 ;允许数据发送吗？
pop ax ;发送
mov dx,DATA_
MOV CX,Device_ID
MOV DX,Vendor_ID
MOV SI,0
INT 1AH
JNC InitPCI3 ;是否存在Star PCI9052板卡
LEA DX,msg1
JMP InitPCI1
InitPCI3: MOV DI,PCIBAR3
MOV AH,0B1H
MOV AL,09H
INT 1AH ;读取该卡PCI9052基地址
JNC InitPCI4
LEA DX,msg2
JMP InitPCI1
InitPCI4: AND CX,0FFFCH
MOV IO_Bit8_BaseAddress,CX
RET
InitPCI ENDP
ModifyAddress PROC NEAR
ADD COM_ADD,CX
ADD PA_ADD,CX
ADD PB_ADD,CX
ADD PC_ADD,CX
RET
ModifyAddress ENDP
Exit: MOV AH,4CH
INT 21H
END START
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第1个回答 2011-12-24
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